Downs Syndrome
Uploaded by asiajewel on Jun 10, 2002
Introduction
In the United States about one in every 1000 live births is a child with Downs Syndrome. Downs Syndrome affects all races and genders. It is caused by extra genetic material on the twenty-first chromosome. There are three different types of Downs Syndrome known to man today. The first case of reported was in the late 1950’s, but the condition was identified in the late 1960’s. In most cases it is simple to identify an individual with Downs Syndrome. In most cases the facial features give it away, but today with new technology it is easy to make these features less noticeable. While there is no “cure” for Downs Syndrome, there are treatments that can help patient’s live full and happy lives. These treatments are not proven to be one hundred percent affective, but they have helped many patients to live happier, more comfortable lives. The Medical problems are involved with Downs Syndrome are more severe in Downs then they would be in that of a healthy child.
What is Downs Syndrome?
Named for a British Doctor, John Langdon Down, who first clinically identified the condition in 1866, Downs Syndrome is a genetic condition caused by extra genetic genes from the twenty-first chromosome(figure 1). It is unknown what causes the extra chromosome, but tit produces extra proteins, and when the extra chromosome is present the production of the proteins are doubled and causes the typical Downs Syndrome features. (“The Story of Downs Syndrome”)
What are the Different Types of Downs Syndrome? Figure 2
Downs Syndrome, sometimes refereed to as DS or Downs, can occur in three different forms, Trisomy 21 (figure 2), Translocation, and Mosiac. The most common of the three, Trisomy 21, affecting 95 percent of patients with Downs Syndrome is caused by an extra 21st chromosome. Usually a person has twenty-three pairs of chromosomes, each made up of genes, but in Trisomy 21 (nondisjunction) the person has three number 21 chromosomes instead\ad of two. This occurs when the formation of the egg or sperm a double-dose of the chromosome goes to the egg or sperm. Usually when the egg or sperm are forming they split so that only one chromosome is in the egg or sperm, but in trisomy 21 they don’t split causing the individual to have more chromosomes then they need.
In the second form, translocation, which occurs in about three or four percent of Downs cases. In...